Fuel-burning system



April 7, 1931. K, A. MAYR 1,799,758

FUEL BURNING SYSTEM Original Filed Dec. 17, 1927 2 Sheets-Sheet l April7, 1931. K. A. MAYR 1,799,758

FUEL BURNING SYSTEM Original Filed Dec. 1'7, 1927 2 Sheets-Sheet 2avwamtoz I A M al oznu j Patented Apr. 7, 1931 UNITED STATES PATENTOFFICE mm. A; mm, or meronx, :u. 1., ass renon 'ro sImmNs-scaucxnnrwnmmmnensnnnscmr, or smmnnssranr, ma 3mm, GERMANY, a conroaanon or ennmmrFUEL-BURNING SYSTEM Original application filed December 17, 1927, Serialll'o. 240,657. Divided and this application filed Kay 24,

' 1928. Serial No. 280,195.

This invention relates to control means for a fuel burning system andthe present application constitutes a division of my copendingapplication, Serial No. 240,657, filed December 17, 1927.

The invention has for one of its objects the rovision of a novel controlor safety device or warnin an operator of an improper operating con'tion and for cutting off the total 10, fuel su ply under certainoperating conditions w ere otherwise damage would be in curred. 1 t

A further object of the present invention resides in the provision ofmeans automatically brought into operation for shutting off the fuelsupply in1 the elilent that there is not a pro er air sup y to t e aaratus.

A fhrther obj dct of the gl 'iasent invention resides in the provisionof a signal with means for automatically calling the same into operationin the event of an improper air supply. her ob ects and advantages w1llbe hereinafter set forth in the accompanying specification and claimsand shown in the drawings, which by wa of illustration show one and apreferred em odiment of the invention.

In the drawings, Figure 1 is a diagrammatic view of asteam :0 plantembodying my improvement.

Fi 2 shows diagrammatically the fuel supp ying system with the variouscontrols. In more detail, referring first to Fig. 1, B represents asteamg'enerator having a'combustion chamber C and a draft inducing fanF. H is a high pressure steam consumer which may exhaustintoa lowpressure line G which may also receive steam from other .low res'sureboilers such as B having drums D. uitable burners are indicated at 36receiving fuel from a line 33.

Referring now to Fig. 2, main su ply tank for i uid fuel. A pump 14withdraws the fuel romthis tank and delivers it to a supplemental orauxili'arytank 15. From this s pplemental tank fuel is withdrawn by apump 22 and delivered through a heating c011 31 disposed in the drum Dto a pipe or conduit 32. Conduit 32 leads toa control valve generallydesignated 32a. Un-

lO designates the der normal operating conditions'the flow of liquidfuel through this valve is as shown, that is, from pipe 32 to conduit33. This conduit may be provided with'a pressure indicating gauge 34 anda thermometer 35 to show the temperature of the oil. Conduit 33 "extendsto the burners generally designated 36. The burners may be provided withcontrol valves 37 so constructed that the fuel supplied to the burnerswill be out off when the b urners are swung out of their normalposition. In this way the fuel is automati- I cally shut off to a burnerwhen this burner is swulg out of the firebox or combustion chamber(Fig. 1) when brought out for inspection or repair.

Referrin again to valve 32a, this valve is provided with valves 32?) and320 which are so connected withthe conduits 32 and 33 and 72a and 72that if the fuel flow through 32 is stopped, for example at 320 or 37, apassage is provided from point 30 to the tank 15 through conduit 72a,valve 32?), loaded spring check or back pressure valve 73 and conduit72.

. Control devices Provision is made for giving a signal such as anaudible signal to the operator in the event that the steam leaving theboiler reaches acertain predetermined temperature. Such a conditionwould arise with certain types of boilers, that the quantity of fuelsupplied is greatly in excess of the water supplied.

Such a condition would cause an excessive superheating of the steam.

There is further provided means for automatically shutting off thesupply of. fuel to the burners entirely in the event that the audiblesignal is disregarded and in the event that the steamtemperature attainsa" stillhigher or injuriouslimit.

Another control which is provided is a control for shutting off thesupply of fuel to the burners in the event that there is nota proper airsupply to the apparatus. Asignal is alsocalled into action in the eventthat the fuel supplied to the burners is shut off due to lack of airsupply. These various controls will now be described, but it will betube connections between such sections of the boiler where a hightemperature rise of the steam flowing therethrough would first benoticeable. This section 50 is provided with a thermostat 51 of anydesired form. Such thermostat is here shown as comprising a tube of amaterial having a high thermal coeflicient of expansion. Fastened to theupper end of this tube is a rod 52 formed of a material with a differentand lower thermal coeflicient of expansion. Disposed adjacent rod 52 isa lever 53 fulcrumed at 54 and carrying .a screw 55 so as to beadjustable in the lever with respect to rod 52. The lever 53 is normallyspring pressed by an adjustable spring 56 so that part 55 is kept incontact with rod 52 and this spring 56 also keeps lever 53 in contactwith its fulcrum. One end of lever 53 is provided with a lost motionforked connection 57 which connection carries one of a pair of contacts58 disposed in an alarm circuit to audible signal 59. Upon expansion oftube 51, contacts 58 will close and cause audible signal 59 to sound.Upon a further movement of the fork 57 such fork will contact with aspring pressed lever 60 carrying on it valve 61. The normal position ofvalve 61 is as shown, but in the event of excessively high temperatureconditions it is shifted to lower position to connect a conduit 62 toatmosphere through port 63. 64 designates a suitable supply ofcompressed air. This compressed air normally is in communication withconduit 62 through conduits 65 and 66,-

valve 67 being in the position shown. Conduit 62 in turn leads through atwo-way valve 68 to a cylinder 69. Within the cylinder is a plunger 70which is provided with an adjustable spring 70a. The plunger 70 isnormally held in the lower position as shown by the pressure of the airfrom tank 64. However, upon the opening of 62 to atmosphere, valve 61will shut off the air supply from the conduit 66 and will release thepressure of ,the air within the cylinder 69. Thereupon plunger 70 willmove upwardly under the impulse of its spring and shift valves 320 and32?) from the position shown to upward position. By this action the fuelflowing through conduit 30 will be diverted into a conduit 72 anddirected back to the supplementary supply tank. In this way the supplyof fuel to the burners will be cut ofl". To prevent the pressure on thefuel being wholly released, which might cause volatilization of the fuelin coil 31 or in other parts of the system, a loaded valve 73 isprovided to maintain a pressure upon the fuel irrespective of itsdiversion back to the supplementary supply tank.

It will be understood that valve 73 is set for a relatively lowerpressure than that of the normal operating pressure of the burners.

When the pressure in the system beyond the filters 28 (i. e. in 30, 31,32, 33, etc.) raises to an excessively high point which might occur forexample when all burners are shut ofl, this excessive pressure acts onthe area of valve 32?). This causes an opening of said valve as wellagainst the air pressure in chamber 69 and the oil then flows to tank 15through conduit 72.

For circulatin and recirculating the oil to warm the fuel lines instarting up the plant, valves 32?) and 320 are in the position as shown.Hand operated valve 1 which is normally closed is, during the warming upperiod, opened. The oil then circulates as follows: through heater 31,conduit 32, valve 320, conduits 33, 2, 3 and 72 back into tank 15.

The means for cutting off and diverting the fuel flow in the event offailure or insufliciency of air supply will now be described.

80 in Figs. 1 and 2 designates a pipe which leads to a gas duct of theboiler which is readily susceptible to changes in draft or air supply.With proper running conditions there will be a considerable vacuuminduced in pipe 80 which will maintain a diaphragm 81 in the positionshown and against the tension of spring 82. Upon a certain degree oflowering or complete failure of this vacuum diaphragm 81 will move tothe left under the influence of its sprin and will actuate a leversystem generally designated 83. The details of this lever system aresubstantially the same as heretofore described in connection with valve61. Eventually movement of this lever system 83 will close contacts 84and cause the audible signal 59 to sound and this movement will finallyand subsequently also shift valve 67 from the position shown to anopposite position so that the compressed air supply from 65 will be shutoff and so that conduit 66 will be connected to atmosphere through port85. The ultimate effect will be the same as before, viz. that the fuelwill be diverted from the burners back to the supplementary supply tank.

The control devices just described are emergency devices. It is not theintent1on that these devices act as operating controls for the normalsupply of fuel to the burners. They are intended to come into action inthe event of inattention of the operator.

The control and signal which is attained under excessive temperatureconditions of the produced steam, forms the subject matter of myco-pending application filed May 24, 1928, Serial No. 280,194.

What I claim is:

1. A fuel burning system including fuel supplying means, a combustionfurnace to which fuel is supplied, means controlled by improper draftconditions in the furnace for its lie

controlling the fuel su plying means for entirely cutting off the uelsupply when such conditions occur in the furnace, an emergency signal,and means for automatically calling the said signal into action to warnthe operator of conditions which will subsequently automatically bringabout a cutting off of the fuel supply.

2. A fuel burning system including a combustion furnace, meanscontrolled by draft conditions in the furnace for first giving a signalof improper draft conditions, and means controlled by the aforesaidmeans for subsequentl shutting the fuel supply to the furnace if t eWarning is disregarded.

In testimony whereof I hereto aflix my signature.

KARL MAYR.

